Chemical Reactions WS1
| (Q.1) Why do we apply paint on iron articles? | ( 2 Marks ) |
| (Q.2) Oil and fat containing food items are flushed with Nitrogen. Why? | ( 2 Marks ) |
| (Q.3) What happens when an iron nail is dipped in copper sulphate solution? | ( 2 Marks ) |
| (Q.4) Why should magnesium ribbon be cleaned before burning in air? | ( 2 Marks ) |
| (Q.5) A solution of a substance ‘X’ is used for white washing. (a) Name the substance ‘X’ and write its formula. (b) Write the reaction of the substance ‘X’ named in (a) above with water. | ( 2 Marks ) |
| (Q.6) What do you understand by corrosion? | ( 3 Marks ) |
| (Q.7) Explain the oxidation in terms of gain or loss of oxygen with examples. | ( 3 Marks ) |
| (Q.8) What is a precipitation reaction? Give example. | ( 3 Marks ) |
| (Q.9) Write two uses of decomposition reactions. | ( 3 Marks ) |
| (Q.10) What is the difference between combination and decomposition reaction? Give one example of each type. | ( 3 Marks ) |
| (Q.11) Why is respiration considered an exothermic reaction? Explain. | ( 3 Marks ) |
| (Q.12) Write the balanced equation for the following chemical reactions- (a) Sodium + Water Sodium hydroxide + Hydrogen (b) Barium Chloride + Aluminium Sulphate Barium Sulphate + Aluminium Chloride (c) Hydrogen sulphide + Oxygen Water + Sulphur dioxide | ( 3 Marks ) |
| (Q.13) What are exothermic and endothermic reactions? Give examples. | ( 3 Marks ) |
| (Q.14) Explain the terms oxidizing and reducing agents. | ( 5 Marks ) |
| (Q.15) What is the difference between displacement and double displacement reactions? Write example of each reaction. | ( 5 Marks ) |
| (Q.16) What do you understand by a balanced chemical equation? Why should the chemical equation be balanced? | ( 5 Marks ) |
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